FIELD OF THE INVENTION
The present invention is directed to relays that are plugged into plug bases and, more specifically, to a combination relay and plug base whereby the connection between the relay and the plug base is waterproof and secure. In this context, relay is also understood to mean a so-called relay module, in which further circuit elements, such as resistors and diodes with the associated conductor tracks, are arranged in the housing in addition to the actual relay system.
A large number of possibilities have already been described for the sealing of relay housings, for example the potting of housing gaps with liquid and subsequently curable potting compound. It is also known (DE 43 37 505 C1) to coat wall regions between base or baseplate, on the one hand, and cap, on the other hand, with an elastomer layer using the two-component injection-molding process and thus to achieve the desired sealing when the housing parts are pressed onto one another.
If, however, a relay is inserted into a plug base, as is customary in motor vehicles, for example, then the plug connection between relay and plug base remains unprotected, even if the relay itself is sealed. Since such plug bases, particularly in the engine compartment of motor vehicles, are frequently exposed to severe fouling or moisture, it has been customary to date to insert additional sealing rings between relay and plug base in order to protect the plug connection.
EP 0 400 434 B1 furthermore discloses, for the connection of an electrical module, in particular of a relay, using an additional encasing housing, into which the relay is inserted. The encasing housing has a seal on two sides, namely, on the one hand, in the region of the plug connection, where a radial seal is provided in a region of overlap between plug base and encasing housing, and, on the other hand, on the opposite, open housing side, where a closure cover is tightly inserted by means of a sealing ring that is introduced. However, such an encasing housing causes a considerable additional outlay in terms of production and materials, quite apart from the large space requirement.